Erorr in using an object

Hello.
I have a question for you.
I created a COM object. Before I compiled it on my computer, I checked the option "Register for COM interop" to be "True". After the compilation I register the dll file using "regasm MyDll.dll"
And now when I use it as a COM object in my computer, it works fine.

But on the server it's not the same.
I uploaded the dll and tlb files to the server. Then I executed the command "regasm MyDll.dll".
Then I tried to use the object I got the error "error '80070002' ". It means that the file not found. I tried to copy the dll and tlb files to c:\windows\system32 and also to c:\windows , and it didn't solve the problem.

Does anyone has an idea what to do ? Or how should I install the com object properly?
(I'm so confused with all the registration commands: sn.exe, al.exe, regasm.exe)

Thank you very much !